Assume you read the first 2 links below in my signature.

Pretty much covers most of the issues that cause Lean codes.

Need to see Freeze Frame data and warm idle Fuel Trim info as this will help better understand what is going on.

As for the DISA, it should be closed at idle and it will not open until above about 3500 RPM under heavy load.

You can see the DISA position if you look at the bell crank position, or just remove the DISA and close the valve and plug the exhaust port with your finger, the vale will partially open, but should hold open about 1/4 of the way, not open all the way. If the diaphragm is blown/leaking, this will cause a constant vacuum leak usually for the rear 3 cylinders, same holds true if there is not constant power to the DISA solenoid. This constant vacuum leak will be a small one, not sure it along will trigger a Lean code, but it will add to the problem.

Either the diaphragm is back or for some reason there is not power to the DISA valve. Unplugging the DISA valve connector will allow it to fully open.

Search YouTube for Scotty Smoke Test. Do what Scotty does or make a tester from a related Video.

Also read this thread - http://forum.e46fanatics.com/showthread.php?t=1057387

 

More info

JFOJ, I have used your links for a lot of the work I have done so far.
If you are refering to the freeze frame data when the code is set, then I have that.

From 12/27/2014
With P0171
Fuel system one CL
Fuel system two CL
Calc load percent 27.8
ECT Fahrenheit 204.8
STST space B1 percent 10.2
LTFT B1% 11.7
STFTB2 % 8.6
LTFT B2% 11.7
Engine RPM 1897
Vehicle speed mph six

12/28/2014
P0174 System to lean bank 2
Fuel system one CL
Fuel system two CL
Calc load % 39.6
ECT Fahrenheit 199.4
ST FTB 1% 5.5
LTFT B1% 11.7
STFT B2% 10.9
LTFT B2% 11.7
Engine RPM 2014
Vehicle speed 54 mph

Later same day
P0174
Fuel system one CL
Fuel system two CL
Calc load % 26.3
ECT Fahrenheit 201.2
STFT B1% 6.3
LTFT B1% 11.7
STFT B2% 9.4
LTFT B2% 11.7
Engine RPM 2495
Vehicle speed 66 mph


12/31/2014
P0174 code
Fuel system 1 CL
Fuel system 2 CL
Calc load percent 40
ECT Fahrenheit 199.4
ST FTB 1% 7.8
LT FTB 1% 11.7
ST FTB 2% 8.6
LT FTB 2% 11.7
Engine RPM 2560
Vehicle speed 71

1/2/2015
P0171

P0174
Fuel system 1 CL
Fuel system 2 CL
Cal load % 19.6
ECT Fahrenheit 201.2
STFT B1% 3.1
LTFT B1% 11.7
STFT B2% 7.8
LTFT B2% 11.7
Engine RPM 1652
Vehicle speed mph 43

1-08-2015
P0174
System to lean bank 2
Fuel system 1 CL
Fuel system 2 CL
Calc load "percent 31.8
ECT 203 Fahrenheit
STFT B1% 9.4
LTFT B1% 11.7
STFT B2% 7.8
LTFT B2% 11.7
Engine RPM 2082
Vehicle speed mph 40

P0174
System to lean bank 2
Fuel system one CL
Fuel system to CL
Calc percent 14.1
ECT if Fahrenheit 203.0
ST FTB 1% 6.3
LT FTB 1% 11.7
ST FTB 2% 7.8
LT FTB 2% 11.7
engine RPM 701
Vehicle speed zero

Edit to add following
Feb. 22 2015
P0174
System to lean bank 2
Fuel system one CL
Fuel system to CL
Calc percent 16.9
ECT if Fahrenheit 195.8
ST FTB 1% 6.8
LT FTB 1% 11.7
ST FTB 2% 8.6
LT FTB 2% 11.7
engine RPM 1645
Vehicle speed 40

March 15 2015
P0174
System to lean bank 2
Fuel system one CL
Fuel system to CL
Calc percent 40
ECT if Fahrenheit 197.6
ST FTB 1% 6.3
LT FTB 1% 10.9
ST FTB 2% 7.8
LT FTB 2% 11.7
engine RPM 2532
Vehicle speed 70




P0171 is the secondary code when the P0174 get triggered, but no data from Scan tool.

As for the DISA, it should be closed at idle and it will not open until above about 3500 RPM under heavy load.

You can see the DISA position if you look at the bell crank position, or just remove the DISA and close the valve and plug the exhaust port with your finger, the vale will partially open, but should hold open about 1/4 of the way, not open all the way. If the diaphragm is blown/leaking, this will cause a constant vacuum leak usually for the rear 3 cylinders, same holds true if there is not constant power to the DISA solenoid. This constant vacuum leak will be a small one, not sure it along will trigger a Lean code, but it will add to the problem.

Either the diaphragm is back or for some reason there is not power to the DISA valve. Unplugging the DISA valve connector will allow it to fully open.

Search YouTube for Scotty Smoke Test. Do what Scotty does or make a tester from a related Video.

Also read this thread - http://forum.e46fanatics.com/showthread.php?t=1057387

The DISA does have a constant 12V's but the bell crank never moves. It's difficult to tell if the port is clogged to not allow the vaccum to pull it closed at start up or the solenoid has gone bad.

No cigars for me, I have used a party smoke machine on the car to smoke test for leaks earlier and found an issue with the vent hose from the crank case valve.

I will bypass the booster, but my STFT readings are not that high.

What is the chance that an oil leak from the back of the oil pan or rear main seal is causing the codes? I've watched the vidoes were the valve cover gasket can cause lean codes.

 

Should the valve change positions when the car is started or only when the revs are climbing?
What is the best way to determine if the DISA is operating correctly?

I wouldn't worry about the DISA just yet. Looks like you did your homework and have diagnosed it correctly.

I'll search the ST training manuals for the exact text, but I remember that changeover is a function of RPM and load. As further "proof", a few have done a DISA delete (back when that was a "mod") and didn't end up with lean codes. None that they admitted to, anyway.

I'd follow JFOJ's link and go from there. But if this were my car, the DISA wouldn't be my first suspect after it passed the pin/flap/diaphragm/o-ring test.

 

Freeze Frame unfortunately is usually for the first code captured, so if there are multiple codes, the FF will be for only the first code.

Looking over your FF data, most all of the events are at speed. You have one at 6 MPH, but this was in Dec, you probably have done work since then to resolve Lean codes.

Given the Lean codes are at speed, MAF and fuel pump are the most likely culprits.

Really hard to determine if the MAF or fuel pump/pressure is the issue.

Here is my thought, fuel pump is $125 shipped to your door for a Siemens/VDO if you purchase from the correct place.

The fuel pump I assume is original? The fuel pump will not last forever and it will fail and likely leave you stranded, the MAF will not strand you. So I would recommend a fuel pump and also a filter, but the pump is the most likely culprit between the 2 to cause Lean problems.

Then if the fuel pump does not improve/correct things, I would replace the MAF with a quality unit from a reliable source. Too many Asian counterfeits out there that you need to steer clear of. The MAF will likely be double the fuel pump cost anyway, so this is one reason I replace the cheaper part first.

As with anything, I could be wrong on these items as being the culprit, but probably 95%+ are the chances that the fuel pump and/or the MAF may be the cause of your Lean codes. Any yes, they both may be contributing to the problem, this is where is gets tricky that a weak fuel pump and a under reporting MAF can both contribute to high Fuel Trims/Lean codes.

Revisit the DISA later, you may have missed a blown diaphragm or may not understand when it is and is not open.

You should be able to actually hear is open about 10-15 seconds after the engine is shut down if you know what to listen for.

 

Thanks for the feedback guys, I will dig into the fuel pump and report back.

 

Please do report back. I have the same year and car as you do with 131,000 mi. and am getting the same 2 codes as you, as of today.......I have not done all the things you have, but will look back over what you said and maybe start checking those things this wkend.
jfof is probably the best person to have guiding you thru this, sounds like you know this though.
Good luck.
If i happen to luckily find anything this wkend i will post.

 

Crazy that you posted this as I had a similar issue with my e46 (87k) yesterday. After filling up the gas tank full, I drove for about 25 miles and the car felt very responsive (as with every full tank, I assume). Parked for about 3 hours then after driving for about 3 miles, I felt a little rumble and sure enough my SES light popped on.

Code reader pulled the same exact two codes. I simply cleared it and it's been good ever since, but I'm monitoring it I guess. Also going to keep my eye on this thread also in case it does become a larger issue.

 

Hi Folks,
I will report back. Work has kept me busy for the last week or so. The only reseach I have been able to do on the fuel pump is take out the back seat, pull the rubber plugs and look. Judging by the silt, dust, and dirt the fuel pump has never been out. I am curious about the fuel pressure, but don't know if I'll get the time to pick up a guage to test anytime soon.

 

I told you I would report back and that's what i am doing. My problem was a hose that goes into the valve cover..split on the bottom, funny how they are NEVER split on the top where you can see them..........anyway do yourself a favor, STOP worrying about fuel pressure and all that sh!t,,,,,you will spend more time trying to check your pressure than just replacing your pump,,,,replace the damn pump,it will take you all of 15 mins. DO NOT do as youtube videos say....... put your seal on the car and then slide your pump into place, simple as it can be, and if it does not cure your problems at least you have the peace of mind knowing that you have no problems with fuel delivery and then you can go from there, but hopefully this will cure your problem.........let us know how things go.

 

^ This person is newer here, but he gets it!

Listen to him, just replace the pump you will remove a BIG source of leaving you stranded and you can control the replacement cost of less than $125 now, if the car leaves you stranded, it WILL cost you at least double unless you are lucky and you are stranded near home and you can wait 2-3 days for a replacement pump.

 

I only get it because of people like yourself, who have taught me. I am just repeating what some of you veterans have said....my way of trying to 'pay it back' so to speak....I don't think i could ever thank some of you vets enough for what you give to this forum, especially yourself.

But I can do one thing, if any of you veterans on the site are ever around Birmingham, pm me as I can and will treat you to Dreamland BBQ and you won't forget it, Now you being from Virginia, i can't say it is the best you have ever had, but it is up there amongst them, i promise you that!

Have a great week and thank you for all you do.

 

Do you ever have a hesitation when accelerating? I had PO171 and PO174 for 4 months and I replaced everything I could think of. DISA, Fuel Pump, Filter, Vaccum Hoses, Spark Plugs. In the end It was the MAF sensor. A bmw technician in my area asked me if I had an ebay filter (which I did) and he said the crappy filter had let contaminates in and damaged the MAF.

 

hahaha, great to hear man.......My lean codes were coming from ripped hoses and crap. JfoJ is the best person to listen to for me as he is trying to get you not to throw a ton of money on parts, but to do what needs to be done anyway.

These sorry ass rubber and plastic hoses suck, they will split everywhere. I am actually doing what he says, especially with the ccv and hoses at least then you don't have to worry about it for a long time. .....I can't say anything that JfoJ hasn't already said, but remember....for a short time with a cracked hose, duck tape is your best friend.

I sorry that i can't remember what all you have checked out and don't have time to recheck, but i check all the hoses a week ago or so and found that the one going into the valve cover was split on the botton, duct tape, no codes, and of course as i have said i will replace all this ****, just not for a couple of weeks, maybe one....lets us know what ya find, if you will, if anything.

 

hahaha, great to hear man.......My lean codes were coming from ripped hoses and crap. JfoJ is the best person to listen to for me as he is trying to get you not to throw a ton of money on parts, but to do what needs to be done anyway.

These sorry ass rubber and plastic hoses suck, they will split everywhere. I am actually doing what he says, especially with the ccv and hoses at least then you don't have to worry about it for a long time. .....I can't say anything that JfoJ hasn't already said, but remember....for a short time with a cracked hose, duck tape is your best friend.

I sorry that i can't remember what all you have checked out and don't have time to recheck, but i check all the hoses a week ago or so and found that the one going into the valve cover was split on the botton, duct tape, no codes, and of course as i have said i will replace all this ****, just not for a couple of weeks, maybe one....lets us know what ya find, if you will, if anything.

Don't take this the wrong way, but from the hoses and the fuel pump, did you hang the sign for "procrastinator's anonymous meeting canceled tonight, meet again tomorrow"?? :rofl:

Keep at, we will get there some day.

 

Did fuel pump solve all your problems? Lean codes that is. I have the same two but also p2096 and cannot get I the bottom of it

 

Solving problems, naaaa. help some, yes



The fuel pump did not solve all of my problems. But it did appear to help.

Before the pump swap, the light would come back on the way home from work. Which was the second start cycle that everything got good and warm with a cool down in-between, if that make sense. Generally about 35 miles.

After the swap, the car made 5 trip to and from work before the light came on, about 200 miles with other errands.

 

You've replaced a lot of he typical stuff.

I'm wondering if intake gaskets are not sealing correctly. Pulling in unmetered air the same as a disa leak would do.

These items would probably cause high fuel trims at idle as well though.

 

Other things to consider



I have had that thought too. I replaced the oil filter housing gasket in the last 6 months. I couldn't see the source for anything. So, I cleaned the underside of the car with water and watched for the oil to reappear. I googled "Oil leaks on front of BMW" and hit paydirt. Found out that it was a common problem. Never seen a gasket/O-ring shaped like that, they have all been round or flat.
I smoke tested the car with a contraption made from a party fog machine about a year ago and found a bad hose on then CCV then. Haven't used it since. The reference from jfoj for Scotty smoke test turned up a guy puffing on a stogie. I have enough compulsive habits without picking up another. :tsk:

Find someone with a good running car
Have them log maf k/sec
That's how we diagnosed my maf as being bad.
My numbers were 15% lower than his.....no cel lights.
My fuel trims were off

I have seen that info in one of the scanner tools, but I didn't take pictures of it at the time and don't remember the numbers. I will have to go looking for that.

I don't know anyone else with a similar car to swap the part with for trouble shooting.

Not sure about using the Hyundai part. I would need to do lots of research.

Thanks for the responses

 

Hmm thank you bolted to floor.

I'm thinking fuel pump is it for me. I've replaced air filter, fuel filter, MAF, DISA, cold weather CCV, both post cat o2 sensors, and all SAP hoses. Still code comes back fast I have to get my hands on freeze frame and fuel trims but I'm starting to think my fuel pump is having a soft fail. 155k and it's probably original pump... Thoughts?

 

Story time

Hmm thank you bolted to floor.
I'm thinking fuel pump is it for me. I've replaced air filter, fuel filter, MAF, DISA, cold weather CCV, both post cat o2 sensors, and all SAP hoses. Still code comes back fast I have to get my hands on freeze frame and fuel trims but I'm starting to think my fuel pump is having a soft fail. 155k and it's probably original pump... Thoughts?

I was googling the codes when I stumbled across jfoj's post. It well written by my standards, very informative, and it gives a logical approach to solving the problem starting with the cheapest parts first. That appeals to me.

To me, these lean code problems are a lot like the results from an accident investigation. There is never just one thing that lead to the accident, it was the result of several things that went wrong.

These cars are not new anymore, they have lots of miles on them. Some of the parts are worn in and some of them are worn out. The biggest problem I am having with the advice given is making sure I comprehend it well enough to provide the information that is requested.

Thanks for the responses

 

You also have the 325ci which has an option of getting a vdo Hyundai sonata maf sensor for much less than the oem.

 

That actually makes a lot of sense to me, not sure , but it makes good sense to me.

 

Find someone with a good running car
Have them log maf k/sec
That's how we diagnosed my maf as being bad.
My numbers were 15% lower than his.....no cel lights.
My fuel trims were off

 

My smoke machine used toy train oil and a diesel glow plug to burn it.
Air compressor at low volume to push it. A ton of smoke ensued.
Found......nothing
Bad maf

 

The sonata maf sensor just needs to be Siemens/vdo.
There is/are threads on here documenting it to be a direct replacement and working very well. It's been tested and showed excellent results.
My 330 could not use it unfortunately.
The 325 however....can and it can be had for a lot less on the price.

 

http://forum.e46fanatics.com/showthread.php?t=783659

Here is the original link.
It has been documented on several forums

For $150.....I would replace it for the heck of it. The maf is so hard to diagnose. Mine was $350
The amount of time I spent was worth more than $150 trying to get it figured out

 

This problem cured!!

Well....I finally came off the wallet and bought a new MAF sensor. I got the VDO unit from ECS Tuning. It has cured the problem. The old MAF looked to be the original.

Several hundred miles and no lean codes. :excited: :woot: :excited:

I owe a lot of thanks to all of y'all for helping out. :bow:

I will try to update the first post to reflect more info.